Carburetor



M. GOUDARD Jan. 26, 1932.

CARBURETOR Filed Nov 4, 192

Patented Jan. 26, 1932 @FFEQE MAURICE eoUnARn, or ivn rL Y snnsnmn,FRANCE onrmunnron Application filed November 4, 1925 Serial No. 66,808,and in Belgium December 17, 1924.

This invention relates to carburetors having a plurality of sprayingnozzles controlled by a throttle valve. r

This invention is an improvement on the invention disclosed in mycopending application for carburetors, S. N. 7 54,622, filed December 8,1924.

With known carburetors comprising a principal nozzle and a slow speednozzle delivering at all speeds of the engine, it is found that thecarburation'is satisfactory at starting and when running full speed, butwhen the valve is turned into position very close to that in which it iscompletely shut, a poor mixture is produced.

The insulficient output in almost closed position produces the so calledgap in carburation at the'slow speed limit and is due to the fact thatthe strong suction which is exerted on theslow speed nozzle in theposition where the valve is almost closed-diminishes too rapidly whenthe latter moves into the position corresponding to a slightly largeropening.

With certain constructions, the slow speed nozzle contributes anexcessive amount for fast running. This is particularly the case whenthe edge of the valve covering the auxiliary full inlet opens in theupstream direction. In such constructions, the terminal orifice of theconduit of the slow speed nozzle in the conduit of the principal nozzleis always in the zone of suction created by the movement of the valveinto slightly open position. The slow speed nozzle therefore contributestoo much mixture at part way open positions of the valve.

The present invention has for its ob ect to remedy the poverty orinsufliciency of output at the end of the slow speed period and toremedy its excess towards the end of the full speed period.

In order that the invention may be clearly understood, it will now bedescribed with reference to the accompanying drawings, but it is to beobserved that the description and drawings are given merely by way ofexamle. p Figs. 1 and 2 show, in vertical section, a portion of twocarburetors having a full speed nozzle and a slow speed nozzle, thecarburetors being constructed according to the invention;

As regards all the parts of the carburetor other than the obturatingvalve or throttle, these are constructed and arranged in the mannershown in my copending application S. N. 7 54,622 above referred to,including for instance a constant level chamber 0, provided with a float0'.

d is the body or principal conduit of the carburetor, in which islocated the principal nozzle a. v

e is the slow speed conduit opening into the body (Z by means of ahorizontal passage.

An auxiliary nozzle Z2 is located in the axis and at the bottom of theslow speed conduit 6.

As regards the :obturating or throttling device, this is so arrangedthat in the closed position aperipheral portion thereof covers or masksthe opening of the slow speed conduit e. WVith this end in view thedevice'is preferably formed as a butterfly valve f turning about an axisperpendicular to the axis of the carburetor, and, in the case of thecarburetor shown at Fig. 1, located substantially in a planeperpendicular to the axis of the body of the carburetor passing throughthe edge of the orifice of the slow speed conduit towards the nozzle.

The butterfly valve is provided on the side directedtowards the slowspeed conduit with an enlarged or thickened portion f adapted in theclosed position of the valve to cover or mask the said conduit 6.

According to-the principle of the invention the want of an'adequatedelivery from the passages, when passing from slow speed towards highspeed, is remedied by providing the arrangements shown at Figs. 1 and 2.

In the embodiment shown at Fig. 1 the for ward edge, that is the edgetowards the nozzle, of the opening of the slow speed conduit 0 islocated substantially in the transverse plane passing through the axisof the valve 7". The valve is provided with the enlarged portionfiwhic'h in this case is formed spherical in the neighborhood ofthe slowspeed orilice where coming into contact with the wall of theprincipalconduit; From this spherical surface extend a series of passages openingon the suction side of the valve. These passages increase progressivelyin diameter, in such a way that as the valve is opening passages ofprogressively greater diameter come opposite the slow speed orificeWhile the enlarged portion of the valve is still covering such orificeand is moving upwardly With the flow of carburcted air.

The result of this arrangement is that a progessively increasing suctionis brought to bear upon the slow speed nozzle, since air is being drawnthrough passages t', m and n of progressively increasing section.

Referring to Fig. 2, Where the opening of the slow speed conduit may beslightly down StlGiIIHW'ELl'Gl of a plane perpendicular to the axis ofthe main conduit and passing through the axis of the valve, the valve fis provided with an enlarged portion l" covering the slow speed orificein the closed position of the valve. The edge of this enlarged portiontowards the nozzle may, when the valve is in closed position, liedownstreamward of, or

i in, a plane perpendicular to the axis of the main conduit and passingthrough the valve axis. In the said enlarged portion is, a singlepassage 2" is provided so arranged that in the closed position of thevalve, the passage opens at one end on the suction surface of the valve,

and at the other end slightly upstreamward of the terminal orifice ofthe slow speed passage. The upstream edge of the enlargement produces,in the slightly open position, a strong suction on the slow speed.conduit and as the passage c" approaches the terminal orifice of theslow speed passage it gradually increasing output section or deliverypassage is provided. increasing suction on the slow speed nozzle isobtained through the combination of the single passage in the valve withmeans for gradually increasing the radial flow of air over the surfaceoi the opening of the conduit 0, during the time that the upstream edgeof the enlargement 7c maintains a strong suction at the level of theopening of the slow speed conduit 6.

It Will be observed that both as regards the constructions illustratedat Fig. 1 and Fig. 2,

the enlarged portion of the valve opens in the direction of movement ofthe air, the result being that in both cases in the open positions ofthe valve the suctions upon the principal nozzle and upon the slow speednozzle are substantially equal. Under these conditions, an excessiveoutput is not to be feared at high speeds from the slow speed nozzle.

As will be clearly understood and as appears moreover from What hasalready been stated, the invention is not limited in any Way to themethods of application or the'constructional embodiments moreparticularly described, but all modifications are included fallingWithin a fair interpretation of the claims.

What I claim and desire to secure by Letters Patent of the United Statesof America is 1. A carburetor comprising in combination a main nozzle,an auxiliary nozzle, a main mixture conduit, an auxiliary mixtureconduit having a terminal orifice in said main conduit. and a valvepositioned in the main conduit so as to obstruct said terminal orificeWhen in closed position, said valve being operable to gradually uncoversaid terminal orifice While simultaneously opening passage through themain conduit, said valve further having a plurality of passages ofdifierent section therethrough for coaction with the terminal orifice.

2. A carburetor comprising in combination a main nozzle, an auxiliarynozzle, a main mixture conduit, an auxiliary mixture conduit having aterminal orifice in said main conduit, and a rotatable valve positionedin the main conduit so as to obstruct said terminal orifice when inclosed position, said valve being operable to gradually uncover saidterminal orifice While simultaneously opening passage through the mainconduit, said valve further having a plurality of passages therethroughof diiieren-t sections, said passages being positioned so as to alignsuccessively with the terminal orifice during the opening movement ofthe valve in the order of their increasing sections.

In testimony whereof I have hereunto my hand.

MAURICE GOUDARD.

